Signaling system



April 30, 1940. F. R. BRIDGES 2.199.279

' SIGNALING SYSTEM Filed May 27, 1956 4 Sheets-Sheet 1 wwm- l IOI) T\ I I03] 43 78 l I I xs v x5 M m m B--- Fla. 3

l/VVE N TOR FRANK ROWLANO BRIDGES ATTORA 'EY April 30, 1940. BRIDGES 2.199.279

SIGNALING SYSTEM 4 Sheets-Sheet 2 Filed ma 27, 1936 $9 INVENTOR I r FRANK ROWLAND BRIDGES 57 156% FIG. 7 i ATTORNEY April 30, 1940. F. RQBRIDGES 2.199.279

SIGNALING SYSTEM 4 Sheets-Sheet 5 Filed May 2'7, 1956 1. 4i llulv uz @jM INVENTOR fPA/VK ROM/7ND BRIDGES A TTOANE) F. R. BRIDGES SIGNALING SYSTEM April 30, 1940.

Filed May 2'7, 1936 4 Sheets-Sheet 4 FRANK ROWLAND BRIDGES ATTORNEY Patented Apr. 30, 1940 Frank Rowland Bridges, Needham, Mass., as-

signor to The Gamewell Company, Newton Upper Falls, Mass a. corporation of Massachusetts Application May 27, 1936, Serial No. 82,085

. Claims.

This invention relates to signaling systems and more particularly to so-called auxiliary signaling systems whereby a device for formulating code signals in a main circuit may be caused to 5 operate from a station or stations associated with an auxiliary current path.

In systems wherein such an auxiliary current path is energized from the main circuit, and is therefore frequently referred to by the term auxiliary loop, it is customary toprovide an electromagnet with its winding serially connected in the main circuit. Such magnet is-under normal conditionsfshort -circuited or shunted by the auxiliary loop,. and becomes energized upon interruption or impairment of the current path throughthat loop. Resultant from such interruption, signal formulating mechanism is caused to operate for the purpose of formulating code signalsover the main circuit. Systems of this character are frequently referred-to as being of shunt type.

Shunt type auxiliary systems have heretofore been extensively and advantageously used although, in the course of such use, it has been 0 found needful to restrict the resistance of the shunt loops to a distinctlyminor fraction of the resistance of the magnet windings respectively shunted thereby. Such relationship of-resistances was found necessary in order to minimize or unimpaired continuity of their respective shunt loops.

45 Another object is to render it practical for the resistance of shunt loops as described to equal more nearly or fully, or even to exceed, that of the current path through the magnetsthey'shunt, without thereby rendering the respective systems 50 more susceptible to signal formulating-activity responsive to energizations of such magnets as may occur without impairment of the current,

path through the shunt loop. r

Another object ofthis invention is to provide 55 such a signaling system wherein effective enerm occasions when the shunted magnet would un-' mined degree of the excitation of one of said sume a position for causingactivation of the regization of the main circuit magnet causes complete or partial isolation of the shunt loop from V the main circuit and from parts or components thereof.

' mechanism, for rendering the main circuit current path lower or substantially equal in resistance relative to its resistance, prior to initiation of operation of the signal formulating mechanism.

For the attainment of the foregoing objects pursuant to a general aspect of this invention, there is associated with ,a movable part, which suitably governs activity of the main circuit signal formulating mechanism, electromagnetic structure including two, windings. One of said windings is for association with the main current 'path for energization from the current source therefor and the other of said windings is for energizable association with a current path in shunt relationship to said first winding.

More specifically, the electromagnetic structure involves parts and their arrangement whereby a certain functionally significant activation of said movable part will result, during a pedeter- 5 windings, only during predetermined impairment of excitation of the otherof said windings. For example, the structure may be so arranged and proportioned that themovable part will asleasing or tripping mechanism only. when the excitation of 'a certain oneofsaid windings is at least as great as a predeterminedminirnum at a time when the excitation of the other of said windings does not exceed-a predetermined maximum; or, in certain embodiments of the invention, when the differential between the excitations of such windings exceeds. a predetermined value. 3 h i For the attainment of the foregoing objects in accordance with one of the more specific forms or species of this invention, two electromagnet windings are appliedand connected in such relationship that currentjflow of intended normal directions and intensities therethrough will cause each winding to oppose and substantially neutralize the other.

In accordance with another form or species of this invention, the movable part is magnetically retained against movement responsive to energization of one winding throughout intended energization of the other winding.

In accordance with still another form or species, the movable governing part is arranged for actuation responsive to energization of one winding, and a detent or other restraining means is provided for blocking such actuation of the governing part responsive to energization of the other winding.

In further practice of this invention, contact mechanism is associated with each of the fore-v going specific forms or species and is arranged to function concurrently with the attainment of the releasing or tripping positioning of the movable part. Such functioning of the contact mechanism renders effective shunt paths around certain of the magnets, effects isolation or disconnection of the shunt loop from the main circuit, and/or alters the conditioning of current paths for effecting manifestation of so-called local alarms or indications.

Other characteristics of this invention will appear from a consideration of the following detailed description, taken in connection with the accompanying drawings forming a part of this specification. It should be understood, however, that the embodiments illustrated, though practical, are by no means the only embodiments which the invention may assume, wherefore the invention is not confined to any strict conformity with the showing of the drawings, but may be changed and modified in various particulars, so long as such changes and modifications make no material departure from the salient features of the invention.

Like characters of reference denote corresponding parts throughout all the views presented by the accompanying drawings, in which:

Figure 1 is a diagrammatic representation of an auxiliary signaling system embodying a specific form of this invention which is suited for certain operating conditions;

Figs. 2, 3, 4, 5, 6 and '7 are fragmentary representations of electromagnetic controlling means and certain electrical connections embodying other specific forms of this invention suiting same for different operating conditions;

Fig. 8 is a rear elevation of releasing mechanism suitable for association with the system of Fig. 1; Fig. 9 is an isometric view of the releasing mechanism of Fig. 8, with certain parts broken away and displaced in the interests of more clearly disclosing operating structure;

Fig. 10 is a fragmentary view of certain parts of the releasing mechanism of Figs. 8 and 9;

Figs. 11 and 12 are respectively front and side elevations of the releasing mechanism of Figs. 8 and 9;

Figs. 13 and 14 are elevations of portions of the circuit controlling devices of Figs. 8, 9, 11 and 12; and

Fig. 15 diagrammatically indicates a manner of employing certain features of this invention with an auxiliary circuit having independent current supply.

System with dz'fierential windings The signaling system indicated in Fig. 1' comprises a main circuit MC, an auxiliary or shunt loop SL and a local alarm or supervisory loop LA.

The main circuit MC comprises conductors for serially connecting the signal formulating devices or stations 21, 22, 23 and 24, together with the recording or manifesting device RD, across the terminals of a current source CS.

A signal formulator or signal formulating mechanism is serially included in the main circuit and is diagrammatically indicated as comprising a pair of normally closed signal formulating contacts 31, a code Wheel 32 and a tracer or key break lever 33 for imparting (to the contacts 31) code signal formulating actuations representative of the contour of said wheel 32, so that rotation of this wheel may cause a response of the device RD recognizable as characteristic of the signal formulating station 21, which station, in the instance shown, would be recognized by manifestation of the code number 221.

Associated with the signal formulating mechanism just described, there may be electromagnetically controlled releasing or starting mech anism of suitable well known type, however, for convenience of illustration and description, it will be herein assumed that the releasing mechanism is of the type more fully indicated in Figs. 8 to 14.

Such releasing mechanism includes an electromagnet 41 and associated structure having a Set and a Not set positioning, together with means whereby such structure will be moved from the first to the second named one of said positionings responsive to effective or functional energization of said magnet in a manner which will be hereinafter more fully explained.

Circuit controlling or conditioning mechanic is associated with such structure for actuation thereby, which mechanism comprises the movable contacts 5|, 53 and 55 and the stationary contacts SI, 63, 65 and 61.

The relative formation of the contacts 51, 53, 55, 61, 53, 65and 61 is such that, during movement of said contacts 51, 53 and 55 (incident to rotation of a spindle 141 as will be hereinafter more fullly explained) contact 5| will act to connect contacts BI and 63 and: contact 55 will act to connect contacts 65 and 61, at all times except when contact 53 serves to connect contacts 6| and 61.

The electromagnet 41 has applied thereto a main circuit or tripping winding 43 and a shunt loop or latching winding 45. The winding 43 is serally included in the main circuit MC. The contact BI is connected to the main circuit at one side of the winding 43 and an end of the winding 45 is connected to the main circuit at the other side of the winding 43; the remaining end of said winding 15 being connected to the contact 61.

The windings 43 and 45 are so proportioned that when an intended shunt loop is serially connected between the contacts 61, and 51 (as in a manner which will be presently described) the current flow through one of said windings will substantially neutralize the effect upon said magnet 4| of the current flow through the other of said windings.

As shown in Fig. 1, the shunt loop SL comprises conductors serially connecting the auxiliary stations XS between the contacts 63 and 65. Each of said stations may be equipped with circuit controlling mechanism of any desired type, whereby the shunt loop is normally closed and may be interrupted when it is desired to cause activation of the signal formulating mechanism' of the station 2|.

From the foregoing it will be apparent that when the circuit controlling mechanism associated with the releasing mechanism is positioned as indicated in Fig. l, the contacts 6 I, 63, the shunt loop SL, the winding 45 together with the contacts 65, 55 and 61 provide a current path in parallel with the current path through the winding 43. For convenience, the path through the'winding 45 will be hereinafter at times referred to as the latch path and the path through the winding 43 will be referred to as the trip path. Furthermore the electromagnet including'winding 43 will, at times, be referred to as an activating or initiating magnet.

The'electrical characteristics of the trip path should sufiiciently resemble those of the latch path so that, throughout closure of both of said paths, effective energization of the magnet 4| will not result from abrupt changes in strength of current fiow in the main circuit (such, for example, as those incident to signal formulating circuit closures or breaks).

Supplementary circuit controlling mechanism comprising the contacts 1|, 13, 15 and 11 is associated with the releasing mechanism for actuation incidental to transfer of the contacts 5|, 53,55 from their normal or Set positioning as indicated in Fig. 1 to their abnormal or Not set positioning as indicated in Fig. 6.

Supervisory signaling or local alarm mechanism, diagrammatically indicated by the bell 18 operable from the battery 19, is connected to the contacts 13, 15 so that said bell will sound whenever the contacts 5|, 53, 55 are in their abnormal or Not set positioning.

It may be assumed that additional stations such as 22, 23, 24 have signal formulating mechanism analogous to that of station 2|, which formulating mechanism may be supplemented at any or all of such other stations by releasing mechanism therefor having respectively associated shunt loops.

In order to facilitate comprehension of this invention, the releasing mechanism of Figs. 8 to 14 will be now described in greater detail.

As previously explained, the electromagnet 4| contains the windings 43 and 45 and, for purposes of conveniencein description, it may be assumed that the conductors IIlI, I03 are representative of the respective ends of the winding 43, and the conductors I05, I01 are representative of the respective ends of the winding 45.

An armature III, pivotallysupported at II 2, is mounted in responsive relationship to'the magnet 4|; a clip I I4 (see Fig. 12) being provided for suitably limiting the extent of the travel of the armature III.

A retractile spring H6 (see Fig. 12) is applied to the armature I I I and may be supplemented by gravity for moving said armature away from the magnet 4| and yieldingly opposing its movement toward said magnet.

A detent member I3I (see Figs. 10 and 12) is fixed upon the shaft I33 and said shaft is journaled in the frame plates I35, I31 in such relation to the armature III that when saidarmature is in its retracted position the free end of said member I3I may be positioned within a recess in said armature (see Figs. 6 and 10) and engage a wall of such recess to thereby hold said shaft I33 against clockwise rotation. Furthermore the aforesaid relationship is such that when said armature is in attracted position, the wall of said recess is withdrawn from the path of said detent member.

The shaft I33 is connected to the gear I45 through the pinion I43, said gear being journaled upon shaft I 4| for rotation independently thereof.

The ratio between said gear and pinion is such that each revolution of said gear I45 willcause three revolutions of said pinion I 43. The three pins I41, I41, I41 are secured in the side of the gear I45 in equidistant relation and near the periphery thereof for a purpose hereinafter more fully explained.

The handle I5I and dial I53 are fixed upon the front end of the spindle I4I. Said dial carries the indicia Set and Not'set for observation in connection with the arrow I55 marked upon the frame. An insulating disc 51 is secured to the rear end of the spindle I M and has fixed thereon the contacts 5|, 53 and 55. The contacts 5| and 55 are substantially U-shape, having arms extending along respective sides of the insulating disc 51 and interconnected through the inter-' mediate portions extending through the slots IZI and I23 respectively. The contact 53 is applied to the rear side of the disc 51, and no corresponding contact is provided on the front side of said disc (see Figs. 13 and 14).

The sleeve I 6| (see Fig. 12) is journaled upon the spindle I 4| and has the gear I45 fixed upon one end thereof and the ratchet disc I63 fixed upon the other end thereof. Said disc has three equidistant notches formed in the periphery thereof.

An irregular plate I65 (see Figs. 9 and 12) is fixed upon the spindle I4I, said plate being so formed as to provide an arm I 61' for engaging the frame post I69 for limiting the counter-clockwise movement of said spindle, as well as providing the surface I1I for engaging the shaft I33 to limit the clockwise rotation of said spindle.

, A ratchet dog I13 is pivotally attached to the plate I65 in such position that it may enter the notches in the disc I63; A spring I is applied between a pin I11 carried by said plate I65 and a pin I19 carried by said dog I13 for urging movement of said dog toward said disc I63.

The dog I13 is so formed and positioned that, during Not set conditioning of the spindle I4I (at which time the arm I61 of plate I65 engages the frame post I69) the free end of said dog is wedged between the post I69 and the walls of one of the notches of the disc I63, whereby the gear I45 is held against unintended movement.

A flatcoiled spring I8I (best shown in Fig. 12)

has the outer end thereof secured to the frame post I69 and the inner end thereof connected to the spindle I4I, for urging rotation thereof in counter-clockwise direction. An arm I83 moving with the armature III has the free end thereof situated in such relationship to the shoulder I85 formed in the outer surface of the dog I13 that, when the armature III is in attracted position, and the disc I63 is positioned as shown in Fig. 9 (the detent member I3| standing approximately as indicated by solid lines in Fig. 10) the free end of said arm I83 will be in the path of said shoulder I85, so as to prevent rotation of the spindle I4I from "Not set to Set positioning. The aforesaid relative positioning further being such that the free end of the arm I83 will be withdrawn from the path of the shoulder I85, as just described, by retracted positioning of the armature.

The faces of the dog I13 and arm I83 which are adjacent when the releasing mechanism is in 169, has the free end thereof resting upon the Not set position, are so relatively formed that the armature ill will be prevented from assuming attracted position, and so that movement of said dog incident to rotation of the spindle Ml from Set to Not set position will cause the portion of said dog adjacent its pivot to so act upon the arm M33 as to move the armature lll away from the magnet M, irrespective of energization of said magnet.

A leaf spring I81, supported by the frame post periphery of the gear I45 to serve as a stabilizing brake, for retainingsaid gear against accidental displacement during rotation of the spindle MI from Not set to Set positioning.

As indicated in Fig. 11, a projection l9! extends into the path of the pins It? carried by the gear M5, which projection may cooperate in any desired manner with the associated signal formulating device so that the rotation of the gear M incidental to movement of the spindle Ml from Set to Not set positioning will cause displacement of said projection 19! to thereby cause activation of the associated signal formulating mechanism.

For establishing desired connections between the contacts l3, l5 and Ti, a contact "H is carried by the insulating segment 8! which is pivoted at 83 and is connected through the crank pin 85 with the disc 5'5, as best indicated in Figs. 8 and 12, so that when said disc is in Set position, the segment 8! will bring the contact ll into engagement with the contacts l3 and 11; and so that, when said disc is in Not set position, said segment will bring the contact ll into engagement with the contacts 13 and I5.

Operation with differential windings Under normal conditions, both the shunt loop SL and the main circuit MC are closed (contacts 5! and 55 being positioned as indicated in Fig. 1). The current path through the main circuit divides at the main circuit connection with contact 6i and conductor Ifil and at the main circuit connection with the joined ends of the windings 43 and 45'. Due to the relative characteristics of the windings 43 and 45, the magnetic flux induced by current flow through said winding 43 opposes and cancels that induced by current flow through said winding 45, and vice versa;

so that the magnet M has little, if any, attraction current paths, through the windings 33 and 45,.

respectively, have electrical characteristics which do not differ to an extent such as will cause the rate of change in the current flow in one of these paths (resultant from such breaks and closures of the main circuit) to differ sufficiently from that in the other of said paths, as to result in momentarily efiective or functional energization of the magnet M.

Whenever it is desired to cause the contacts 3| to act to formulate a signal in the main circuit MC, the shunt loop SL should be broken, as by actuation of the circuit controlling mechanism at one of. the stations XS. The breaking of loop SL will both cause current flow through winding 45 to cease and current :fiow through winding43 to correspondingly increase, thereby effecting functional energization of magnet 4|.

Energization of magnet M will cause armature II I to move to attracted position, where it will no longer retain detent member I 3!; thus permitting spring [8! to effect movement of the spindle Ml and parts carried thereby in counter-clockwise direction (as viewed in Figs. 9 and 11) until the arm I6! engages the frame post I69.

Rotation of the spindle Ml, as just described, will carry the dial I53 from the position where its indicia Set registers with the arrow I55 to the position shown in Figs. 9 and 11 where its indicia Not set registers with said arrow.

Furthermore, such rotation of the spindle MI will rotate the detent member [3! in a clockwise direction from the position indicated by dotted lines in Fig. 10 to the position there indicated by solid lines, and will also rotate the disc 51 so as to change the relative positioning of the contacts of the circuit controlling mechanism from that indicated in Fig. 1 to that indicated in Fig. 6.

The turning of the gear hi5 incident to the store-described rotation of the spindle Ml will also cause one of the pins IN to engage the projection 19! (see Fig. 11) associated with the signal formulating device, and thus effect initiation of operation of the signal formulating mechanism inclusive of intended rotation of the code wheel 32 and formulating actuation of the contacts 3!.

The movement of the plate I55 during the rotation of the spindle Ml, just referred to, will also carry the dog I13 to a position where it will engage the lower portion of the arm 983. Such engagement will force the armature HI away from the magnet ll, and thereby assure retracted p'ositioning'of said armature notwithstanding the presence of any possible residual magnetism.

Because of the altered positioning of the contacts 5!, 53 and 55 incidental to rotation of the disc 51 to Not set positioning, a current path will be established between contacts BI and 61, through the contact 53.. In addition the portions of the contacts 5'] and 55 shown by Fig. 13 will be withdrawn from the contacts 63 and 65, thereby completely isolating the auxiliary stations XS and associated conductors from the main circuit MC and 'from the windings of the magnet 4!.

From the foregoing it will be apparent that the breaking of the shunt loop SL causes effective functional energization of the magnet 41 which energization, in turn, causes activation of the signal formulating device of station 2!, disconnection of the auxiliary stations XS and the conductors connecting them from the station 2i, and re-establishment of a current path through winding 4'5. Such re-established current path causes the resistance of the windings of the magnet 4|, efiective in the main circuit MC, to be restored to a value substantially identical to that effectiveprior to interruption of the shunt loop- SL.

The movement of the segment 8!, incidental to rotation of the disc 51 to the Not set position, carries the contact H into engagement with the contacts 73 and 15, thereby closing a circuit for effecting actuation of the bell 78, which will thereafter act to sound a local alarm signal.

It will be evident that, after the contacts 5| and 55 have been withdrawn from engagement with the contacts 63 and 65, operability of the main circuit MC will be unimpaired by the establishment of accidental or malicious connections between the ground or a source of foreign electr'omo'tive force and any of the auxiliary stations XS or the conductors connecting them with the station 2|.

be attempted at a time when the current path The importance of this actionwill be more clearly realized if a concrete example is considered. For instance, assume that the system of Fig. 1 is employed for fire alarm service, that effective energizaticn of the magnet 4'I does not cause isolation of the shunt loop from the main circuit and that fires occur in the premises associated with stations 2I and 24. Furtherassume that such fires progress to an extent causingestablishment of connections between the shunt loops respectively associated with such stations 2| and 24 and the earth, or betweenone of such loops and the earth and the other of such loops and an electric lighting or power circuit.

The circuit through the ground connections established with stations 2| and 24 would then form a shunt which would disable all intervening stations, such as the stations 22 and 23. A ground connection established with one loop and a foreign power circuit connection established with the other loop would result in cur'rent'fiow through the main circuit whichwould probably destroy that circuit or, at least, cause any protective devices included therein to act so as to disable the circuit. 7

From the foregoing it will be recognized that complete isolation of the auxiliary shunt loop SL from the main circuit MC renders said main circuit substantially immune from destruction or impairment of operability resultant from the aforesaid assumed ground and/or power circuit connections.

The importance of maintaining at substantially normal effectiveness in the main circuit the resistances of the windings of magnets of the various stations which correspond to the magnet 4| of station 2|, even following the tripping of releasing mechanism, arises from the fact that variations in the resistance of the current path for the main circuit which might otherwise occur would tend to cause variations from thenormal current strength inimical to most eflicient manifestation of formulated code signals, especially in the event that the tripping or releasing mechanisms of numerous stations are concurrently in "Not set condition. j

Correspondingly, if main circuit conditions are such that the resistance of releasing mechanism windings forms a major portion of the total circuit resistance and there is a possibility that many of such mechanisms will be in Not set conditioning at the same time, it would be undesirable that the entire resistances of the wind-' ings of such mechanisms should be short-circuited, as the current flow in the main circuit might, in that event, objectionably increase.

After the current path through the shunt loop has been restored at the station XS from which a signal hasbeen sent, the releasing mechanism may be restored by grasping the handle I5I and rotating itin clockwise direction until the surface III strikes the shaft I33. Such rotation will Withdraw the ratchet dog I I3 from the previously engaged notch of the disc I63 and carry it into engaging relationship with the walls of the' next notch of said disc. As resetting pressure applied to the handle I5I is released, the urge of spring I8I willact (through spindle I4I, plate I65, dog I13, disc I63, sleeve IGI, gear I45 and pinion I43) to rotatethe shaft I33 until the detent member I3I engages and is retained against further rotation by awall in the recess of the now retracted armature I II, as already hereinbefore explained and indicated by dotted lines in Fig. 10. Should restoration of the releasing mechanism throughthe shunt loop is interrupted, rotation of the handle I5I to move the dial I53 from Not set to Set positioning will be arrested, before the Set positioning is attained. This action will be best understood by referring to Figs, 6, 8 and 9.

As indicated in Figs. 6 and 8, the contact 53 interconnects the contacts BI and 61 when the releasing mechanism is in Not set positioning. However, rotation of the spindle I4I for resetting the mechanism results in early withdrawal of such interconnection between contacts BI and 61, and causes contact 5I to interconnect contacts GI and 63 and contact 55 to interconnect contacts 65 and 61 (as indicated in Figs. 1, 2 and 3).

Such withdrawal of contact 53 causes cessation of current flow through latch winding 45, whereupon, at a time when the shunt loop is open or impaired, the entire current of main circuit MC causes winding 43 to effectively energize magnet 4| ,sothat armature II I moves to attracted position. Such movement carries arm I83 into the der is brought against the end of said arm, inci-. dent to ensuing rotation of the spindle I4I, the rotation of said spindle and of the handle I5! and dial I53 will be arrested, thus indicating that the shunt loop is open and that it must be closed before the releasing mechanism can be fully reset.

Should restoration of the releasing mechanism be attempted at a time when the shunt loop has been closed, current flow through winding 45 will be established through said loop following withdrawal of contact 53 from engagement with contacts 6| and 61, so that said loop may take the place of said contact 53 in completing a current path through said winding 45. for neutralizing the Inter-magnet armature For some situations and operating conditions it may be desirable to employ a latch path having electrical characteristics which differ in a substantial degree from those of the latchpath hereinbefore described. In such an event, releasing mechanism analogous to that indicated in' Figs. 3, 9, 11 and 12 may be arranged for response to an armature playing between the poles of twoelectromagnets, as indicated in Figs. 2 and 6. Referring to Fig. 2, the trip magnet MI is so associated with the armature ZI I that movement of said armature toward said magnet 2M -will release the associated detent member I3I (see also Fig. 6). The latch magnet 242 is so associated with said armature 2 that energization of said magnet will oppose movement of said armature from its retracted position, with relation to trip magnet 24 I; which retracted position corresponds to the retracted position of armature III with relation to magnet 4| as indicated in Figs. 1 and 9.

It will be understood that the utilization of separate trip and latchmagnets, as just referred to, will involve the displacement, with relation to the armature, of the mechanism indicated in the lower part of Figs. 9 and 12, the use of a wider armature so that the magnet below the armature may be in a different vertical plane from that of the magnet above the armature, or

other modification along lines which will be clearly understood by those skilled in this art, to the end that the attraction of the armature by the latch magnet will oppose that by the trip mag.- net; the representations of such magnets in Figs. 2,3, 4, 6 and 7 being diagrammatic in character.

The magnets 2M and 242 comprise the windings 243 and 245, respectively, which windings correspond with the windings 4t and 45 of the magnet 4! of Fig. 1.

It has been found that, at least in the utilization of a pair of bar magnets such as indicated in Fig. 2, having their remote ends interconnected by structure afiording a magnetic path of low reluctance, it is desirable that the windings shall be so connected that the ends of the bars adjacent the armature 2H shall be of opposite polarity.

The windings 243 and 245 may, be variously connected relative to the main and loop circuits and contacts. Such relationship may be in the manner shown in Fig. 2, in the manner shown in Fig. 3, or in a manneranalcgous to that indicated in Fig. l, to meet various operating conditions, as hereinafter more fully explained.

Operation with inter-magnet armature The operation of an embodiment of this invention utilizing an inter-magnet armature, as indicated in Figs. 2, 3 and 6, is similar to the operation of an embodiment utilizing difierential windings (as hereinbefo-re more fully explained) except in respects as follows: 1

With parts positioned as indicated in Fig. 2, the attraction of the armature 2%! by the magnet 24! is at all times overcome by the attraction of said armature by the magnet 242, owing to the extremely small gap between magnet 242 and said armature and a comparatively large gap between magnet 24! and said armature.

Throughout energization of the main circuit MC, and irrespective of variations in the strength of current flow through said circuit, it will be evident that the tension of spring H6 will be materially supplemented by the pull of magnet 242 in retaining the armature 2i i in retracted position with relation to magnet 24!.

Interruption of the current path through the shunt loop will cause denergization of magnet 242 and increased energization of magnet 2M,

with resultant movement of the armature 2 to attracted position with relation to the trip magnet 24!.

The releasing mechanism will thereupon act to start the signal formulating device and incidentally to move the armature 2! l to retracted position relative to the trip magnet 24| as hereinbefore more fully explained.

When the shunt loop has been again closed and the releasing mechanism thereafter reset, the reenergization of magnet 242 will hold the armature 2!! in retracted relationship to the magnet 24!.

It will be apparent that the intermagnet armature embodiment of this invention is especially suited for use in situations where the releasing mechanism may be subject to extreme vibration or jarring or to severe mechanical shocks. Such embodiment is also well suited for situations wherein fluctuations in the current strength of the main circuit might cause efiective functional energization of an electromagnet having two independent windings arranged as indicated in Fig. l, as well as in situations wherein the resistance of the shunt loops is subject to variations so 'great that, with either independent windings as indicated in Fig. l or parallel turn windings as indicated in Fig. 5, effective electromagnet energization might result from either extensive increase or extensive decrease in shunt loop resistance.

Due to the extreme advantage at which the magnet 242 acts over the magnet 24! in retainingthe armature 2!! in retracted position relative to said magnet 24!, the inter-magnet arma- U ture embodiment of this invention is well'suited to situations in which the electrical characteristics of the latch path differ materially from those of the trip path. For example, if the conductors for the shunt loop are subject to the shielding influence or enclosing metallic conduit, so that sudden surges may increase the current flow through the trip winding more rapidly than through the latch winding, the comparatively large gap through which the trip magnet 24! must act to withdraw the armature 2!! from the attraction of the magnet 24-! (through its relatively small gap) will prevent unintended tripping of the releasing mechanism. Under such circumstances unintended tripping of said mechanism might occur were the differential windings form employed.

Inter-locking armatures As an example of the numerous possible embodiments of the broader aspects of this inven-. tion, an embodiment thereof is indicated in Figs. 4. and 7 in which a tripping magnet 44! controls a tripping armature 4! i. in a manner analogous to that of the control of armatures HI and 2 of Figs. 1 and 2 by magnets 4| and 24!, respectively.

Associated with tripping armature Mt is a latch armature 4E2 controlled by a latch magnet 442.

Windings 443 and 445 are associated with magnets and 442 respectively.

Armature M2 is so inter-locked with: armature 4H that throughout intended energization of magnet 442 said armature 4.12 will act to re.-

should armature 4 be moved, responsive to the pull of magnet 44I, a distance insuflicient to-trip the releasing mechanism, concurrent energization of magnet 442 will cause armature M2 to arrest the movement of armature 4 toward magnet 44! and force said armature M! to its fully retracted position.

Trip and latch winding characteristics As hereinbefore more fully explained, differential trip and latch windings may be connected as indicated in Fig. 1, so that, during Set conditioning of the releasing mechanism, current will flow through both of said windings and the current flow through one will substantially neutralize that through the other. With such conditioning, interruption of the shunt loop will then cause discontinuance of current flow through the latch winding and increased current flow through the trip winding for accomplishing effective energization of thetrip magnet. Resultant aotion of the releasing mechanism will reestablish current flow through the latch winding so that the resistance interposed in the main circuit by the latch and trip magnet paths will not be substantially altered between Set and "Not' sjet 'positionin'gs of the releasingmech-- anism.- v

'It will be apparent that inter-magnet armature, inter-locking armature and other embodiments of this invention may have corresponding windings connected in an analogous'manner.

For operating conditions wherein it is deemed desirable that, when the releasing mechanism is in Not set condition, the electromagnet windings shall be short-circuited, connections such as indicated in Fig. 2 or in Fig. 3 may be substi-'- tuted for those shown in Fig. 1.

With the indicated arrangement of Fig. 2, one end of the external'shu'nt loop is at all times connected to one end of the latch winding, although the shuntloop is entirely disconnected from the main circuit when the releasing mech anism is in its Not set position. The other end of the latch winding is connected to contact 265, and the remaining end of the shunt loop is connected to contact 263. H The portions of the main circuit which are connected to the ends of the trip winding are also connected to the contacts 256 and 251 respectively.

For situations wherethe shunt loop may be exposed to accidental connection with electro- 'motive force of other circuits or grounds, as

hereinbefore more fully referred to, the connection indicated in Fig. 3 will be found preferable to that of Fig. 2, inasmuch as the shunt loop is here completely disconnected or isolated both from the main circuit and from the electromagnet windings when the releasing mechanism is in Not set position. Disconnection of theshunt loop from the main circuit is accomplished by withdrawal of contacts 5| and 55 from engagement with contacts 36I, 363 and 365, 361 in a manner analogous to that explained in connection with corresponding contacts of Figs. 1 and 2. In the arrangement indicated in Fig. 3, neither the trip nor the latch windings are included in the external shunt loop connected to contacts 36! and 361 therefore tripping of the mechanism to Not set positioning causes complete disconnection of the shunt loop from the electromagnet windings.

As indicated in Fig. 3, the winding of the trip magnet is short-circuited when the releasing mechanism is in Not set positioning. This is accomplished by the utilization of contacts 31I, 313 and 315 of supplementary circuit controlling mechanism which contacts correspond to the contacts 1|, 13 and 15 of Fig. 1. Thus, when the releasing mechanism is in Not set condition, the contact 31I will interconnect the contacts 313 and 315, to which are respectively connected portions of the main circuit communicating with the ends of the trip winding.

To facilitate the testing of the shunt loop of Fig. 3 for open circuits either in the conductors thereof or at the stations XS therein, the contact 53 is arranged to short-circuit the ends of the shunt loop when the releasing mechanism is in Not set position.

Thus, in instances where the shunt loop system extends over a wide area and a station or leasing mechanism may be restored to its fully Set positioning.

For situations where it is desired to utilize releasing mechanism constructed inaccordance with certain features of this invention in association with-a local current source (instead of using'a local shunt loop), an arrangement such as that of Fig. 15 may be employed in which auxiliary stations XSI5 are associated with signal formulating station I52I through conductors whereby current flow from the source LS normally passes through conductors serially including thecontacts of said auxiliary stations, the comparatively high resistance test relay I523, the trip'coil I543 and the latch coil I545. As shown, the mechanism of said auxiliary stations is arranged so that actuation of the contact I525 of any station will cause deenergization of the the contacts of relay I523 and with contact I515 so that saidbell will be caused to sound in the eventof 'current failure in the normal testcurrent path as 'wellas at all times when the releasing mechanism is in Not set condition.

While certain specific embodiments of this invention have been shown and described in considerable detail, it should be understood that this is illustrative only and for the purpose of making clear certain embodiments of the invention, and that the invention should not be regarded as limited to these details, or to any of them, except insofar as such limitations are included within the terms of the following claims, in which it is intended to claim all novelty inherent to this invention as broadly as is permissible in view of the prior art and to cover all of the generic and specific features of the invention herein described and all statements of the scope thereof which, as a matter of language, might be said to fall therebetween.

I claim:

1. Auxiliary starting mechanism for a code signal formulator comprising a trip magnet winding, a latch magnet winding, an armature normally held in an ineffective position and movable into an effective position upon energization of the trip magnet winding and de-energization of the latch magnet winding, activating means for the formulator having a normal set position and a not-set'position, means operated by movement of the armature to effective position for operating the activating means to not-set position, and means for permitting manual resetting of the activating means only during energization of the latch magnet winding.

2. Auxiliary starting mechanism fora code signal formulator comprising a trip magnet winding, a latch magnet winding, an armature normally held'in an ineffective position and movable into an effective position upon energization of the trip magnet winding and de-energization of the latch magnet winding, activating means for the formulator having a normal set position and a not-set position, means operated by movement of the armature to effective position for operating the activating means to not-set position,

means operated by movement of the activating means to its non-set position for positively moving the armature toward its ineffective position, a manual resetting device for the activating means, and means to permit operation of the resetting device only during energization of the latch magnet winding.

3. Auxi ar me nism for a cede si nal formulator comprising a trip magnet winding, a latch magnet winding, an armature normally held in an ineffective position and movable into an effective position upon energization of the trip magnet Winding and de-energization of the latch magnet winding, activating means for the formulator having a normal set position and a not-set position, means operated by movement of the armature to effective position for operating the activating means to not-set position, a manual resetting device for the activating means, and means controlled by de-energization of the latch magnet winding during operation of the resetting device for preventing restoration of the activating means to set position.

4. Auxiliary starting mechanism for a code signal formulator comprising a trip magnet winding, a latch magnet winding, an armature nor.- mally held in an inefiective position and movable into an efiective position upon energization of the trip magnet winding and de-energization of the latch magnet winding, activating means for the formulator having a normal set position and a not-setposition, means operated by movement f the rmature. o e ec v ositio r o erating the activating means to not-set position, a manual resetting device for the activating means, and means operated by the armature, when the armature is in effective position during operation of the resetting device, for blocking movement of the resetting device.

5. Auxiliary starting mechanism for a code signal formulator comprising a trip magnet winding, a latch magnet winding, an armature normally held in an ineffective position and movable into an effective position upon energization of the trip magnet winding and de-energization of the latch magnet winding, activating means for the formulator having a normal set position and a not-set position, means operated by movement of the armature to effective position for operating the activating means to not-set position, a manual resetting device for the activating means, and a blocking arm movable with the armature to prevent full movement of the resetting device if the armature is in its eflective position during operation of the resetting device.

FRANK ROWLAND BRIDGES. 

